//	Metalink Downloader-Chrome Extension
//	Copyright (C) 2012  
//	Developed by :	Sundaram Ananthanarayanan, Anthony Bryan

//	This program is free software: you can redistribute it and/or modify
//	it under the terms of the GNU General Public License as published by
//	the Free Software Foundation, either version 3 of the License, or
//	(at your option) any later version.

//	This program is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//	GNU General Public License for more details.

//	You should have received a copy of the GNU General Public License
//	along with this program.  If not, see <http://www.gnu.org/licenses/>

function SHA1 (fileSize)
{ 
	var object=new Object();
	var total_len=fileSize;

	object.H0 = 0x67452301;
	object.H1 = 0xEFCDAB89;
	object.H2 = 0x98BADCFE;
	object.H3 = 0x10325476;
	object.H4 = 0xC3D2E1F0;

	function initialize(temp)
	{
		object.H0 = temp.H0;
		object.H1 = temp.H1;
		object.H2 = temp.H2;
		object.H3 = temp.H3;
		object.H4 = temp.H4;
	}
	function exportObject()
	{
		return object;
	}
	function cvt_hex(val)
	{
		str="";

		for( i=7; i>=0; i-- )
		{
			v = (val>>>(i*4))&0x0f;
			str += v.toString(16);
		}
		return str;
	};
	this.getResult=function()
	{
		H0=object.H0;
		H1=object.H1;
		H2=object.H2;
		H3=object.H3;
		H4=object.H4;
		return (cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4)).toLowerCase();
	};

	function rotate_left(n,s) 
	{
		t4 = ( n<<s ) | (n>>>(32-s));
		return t4;
	};
 
	function lsb_hex(val)
	{
		str=""; 
		for( i=0; i<=6; i+=2 )
		{
			vh = (val>>>(i*4+4))&0x0f;
			vl = (val>>>(i*4))&0x0f;
			str += vh.toString(16) + vl.toString(16);
		}
		return str;
	};
 	this.update=function(array,lastPacket)
	{
		//var i, j;
		W = new Array(80);
	
		/*
		var H0 = 0x67452301;
		var H1 = 0xEFCDAB89;
		var H2 = 0x98BADCFE;
		var H3 = 0x10325476;
		var H4 = 0xC3D2E1F0;
		*/

		H0=object.H0;
		H1=object.H1;
		H2=object.H2;
		H3=object.H3;
		H4=object.H4;
	
		var A, B, C, D, E;
		var temp;
	 
		msg_len = array.length;
	 
		word_array = new Array();
		for( i=0; i<msg_len-3; i+=4 ) {
			j = array[i]<<24 | array[i+1]<<16 |
			array[i+2]<<8 | array[i+3];
			word_array.push( j );
		}

		if(lastPacket)
		{
			switch( msg_len % 4 ) {
				case 0:
					i = 0x080000000;
				break;
				case 1:
					i = array[msg_len-1]<<24 | 0x0800000;
				break;

				case 2:
					i = array[msg_len-2]<<24 | array[msg_len-1]<<16 | 0x08000;
				break;

				case 3:
					i = array[msg_len-3]<<24 | array[msg_len-2]<<16 | array[msg_len-1]<<8	| 0x80;
				break;
			}

			word_array.push( i );
	 
			while( (word_array.length % 16) != 14 ) word_array.push( 0 );
		 
			word_array.push( total_len>>>29 );
			word_array.push( (total_len<<3)&0x0ffffffff );
		}
	 
	 
		for ( blockstart=0; blockstart<word_array.length; blockstart+=16 ) 
		{
	 
			for( i=0; i<16; i++ ) W[i] = word_array[blockstart+i];
			for( i=16; i<=79; i++ ) W[i] = rotate_left(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);
	 
			A = H0;
			B = H1;
			C = H2;
			D = H3;
			E = H4;
	 
			for( i= 0; i<=19; i++ ) {
				temp = (rotate_left(A,5) + ((B&C) | (~B&D)) + E + W[i] + 0x5A827999) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			for( i=20; i<=39; i++ ) {
				temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			for( i=40; i<=59; i++ ) {
				temp = (rotate_left(A,5) + ((B&C) | (B&D) | (C&D)) + E + W[i] + 0x8F1BBCDC) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			for( i=60; i<=79; i++ ) {
				temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			H0 = (H0 + A) & 0x0ffffffff;
			H1 = (H1 + B) & 0x0ffffffff;
			H2 = (H2 + C) & 0x0ffffffff;
			H3 = (H3 + D) & 0x0ffffffff;
			H4 = (H4 + E) & 0x0ffffffff;
	 
		}
	 	
		object.H0=H0;
		object.H1=H1;
		object.H2=H2;
		object.H3=H3;
		object.H4=H4;
		delete word_array;

	};
}
